
Add a new "sanitize_realtime" attribute, which will correspond to the nonblocking function effect in clang. This is used in the realtime sanitizer transform. Please see the [reviewer support document](https://github.com/realtime-sanitizer/radsan/blob/doc/review-support/doc/review.md) for what our next steps are. The original discourse thread can be found [here](https://discourse.llvm.org/t/rfc-nolock-and-noalloc-attributes/76837)